Achievement of home ownership among post‐war Australian cohorts

Entry costs to home ownership have been rising in Australia since the mid‐1950s but home ownership rates had not fallen by the mid‐1980s. Drawing from a national life history survey carried out in 1986–87, this paper shows that median ages for first time home buying have been declining among successive cohorts over the post‐war era. The paradox of rising entry costs and earlier home buying may be explained by rising labour force participation among women immediately after marriage and awareness of the increasing financial returns from long‐term home ownership. Among the later cohorts, early entry to home ownership appears to have been associated particularly strongly with wives' employment after marriage and husbands' incomes. The findings suggest that access to home ownership in the future may be increasingly limited to young adults having high household incomes.     

Photoresponsive polymeric systems: 1. Mixed monomolecular films of some synthetic polymers and indolinospiropyrans

The properties of mixed monolayer films of photochromic indolinospiropyrans and poly(methylmethacrylate) (PMMA), poly(vinyl stearate) (PVSt), and poly(2-vinyl pyridine) (P2VP) have been studied. It was found that reversible photoinduced changes in monolayer surface-pressure with time occurred in collapsed systems and in mixed films in which the photochrome had been forced out of the polymer monolayer. Mixed films of P2VP and a spiropyran of particular structure could have their inherent stability increased under the action of ultraviolet irradiation on aqueous subphases. This effect appeared to be related to the formation of a physically crosslinked photomerocyanine-polymer two-dimensional network.     

The use of SP2340 glass capillary columns for the estimation of thetrans fatty acid content of foods

Glass capillary gas chromatography (GCGC) on 100-m and 60-m SP2340 columns was used for quantitation of thetrans unsaturated fatty acids in shortenings and fast foods. The separation of thecis andtrans octadecenoates on GCGC was evaluated by preparatory argentation thin layer chromatography. In addition, thetrans content of shortening samples obtained by GCGC was compared totrans content determined by infrared analysis. This research conducted by the Science and Education Administration, USDA, on the commercial foods as reported in this paper was limited to analysis of their lipid compositions. The data are reported solely as factual information and are limited to the samples analyzed. No warranty or guarantee is made or implied that other samples of these products will have the same or similar composition. It is the policy of the USDA not to endorse those commercial products used in research over those that were not included in the research.     

Determining the cost-benefits of ergonomics projects and factors that lead to their success

Managers usually can justify financially supporting a proposed ergonomics project only when it is supported by a sound cost-benefit analysis. The factors to consider and sources of information for calculating the costs and benefits of proposed ergonomic projects are described. Based upon his experience and review of numerous ergonomics projects, the common characteristics of successful ergonomics interventions gleaned by the author are described and then illustrated by actual documented cases.     

Accelerated testing of on‐board diagnostics

Modern products frequently feature monitors designed to detect actual or impending malfunctions. False alarms (Type I errors) or excessive delays in detecting real malfunctions (Type II errors) can seriously reduce monitor utility. Sound engineering practice includes physical evaluation of error rates. Type II error rates are relatively easy to evaluate empirically. However, adequate evaluation of a low Type I error rate is difficult without using accelerated testing concepts, inducing false alarms using artificially low thresholds and then selecting production thresholds by appropriate extrapolation, as outlined here. This acceleration methodology allows for informed determination of detection thresholds and confidence in monitor performance with substantial reductions over current alternatives in time and cost required for monitor development. Copyright © 2006 John Wiley & Sons, Ltd.     

Response of pocket gophers (Thomomys talpoides) to an operational application of synthetic semiochemicals of stoat (Mustela erminea)

This paper reports on laboratory bioassays and a large-scale field trial of synthetic mustelid anal-gland compounds in controlled-release devices designed for operational application to burrow systems of northern pocket gophers (Thomomys talpoides). The field study was conducted in an apple orchard in the Okanagan Valley of British Columbia. In laboratory bioassays, a 1∶1 mixture of 2-propylthietane and 3-propyl-1,2-dithiolane from the stoat (Mustela erminea) and 3,3-dimethyl-1,2-dithiolane from the ferret (M. putorius), dispensed in clay pellets (activated alumina), produced a significant avoidance response by gophers. All resident gophers were permanently removed from 4-ha control and treatment blocks prior to placement of stoat odor in burrows. As indexed by soil mounds, significantly fewer gophers colonized the treatment (40) than the control (68) removal area during a 5.5-month overwinter experiment. There was also a significant difference when comparing the number of mounds between pre-(79) and posttreatment (40) censuses. In addition, most gopher activity tended to occur on the perimeter of the treatment block. Abundance of gophers showed little difference between additional 4-ha control and treatment blocks where gophers had not been removed. The results of this study provide an alternative technique to toxicants for pocket gopher control on forest and agricultural land.     

Influence of digital audio filters on image reconstruction in MRI

This paper deals with the influence of the transient response and group delay of digital filters on the MRI signal and its aspects in image reconstruction. The consequence of digital filtration on the acquired signal will be shown in the time domain (κ-space) for three basic imaging methods-echo scan, radial scan and spiral scan. The influence of the group delay and transient response of filters will be explained and a method will be proposed which compensates both these phenomena while retaining all the advantages of digital filtration. The proposed method is based on applying the principle of signal superposition and on using the consequences of the sampling principle. The method works in the time domain. It is very simple and rapid and does not depend on the properties of the acquired signal or reconstruction algorithm. It will be shown and explained in which cases the transient response can be neglected and in which it has to be compensated. In the end, the results of the proposed methods will be shown for mentioned cases on a simulated signal in the image domain. © 1998 Elsevier Science B.V. All rights reserved.